Use of dry ice for the shipping and packaging of cryopreserved giant grouper Epinephelus lanceolatus spermatozoa

Abstract

The cryopreservation is an important technology for the preservation of spermatozoa in the marine finfish culture industry. However, the high cost of producing appropriate sperm because of broodstocks maintenance and point-to-point transportation can be a major financial burden. The present study was conducted to determine the temperature changes during transferring the cryopreserved spermatozoa of giant grouper Epinephelus lanceolatus from liquid nitrogen to dry ice and their effect on the viability and the motility rate of the spermatozoa. The cryopreserved spermatozoa were transferred from the liquid nitrogen tank into the closed styrofoam box containing dry ice for shipping. The temperature exchange was recorded and the viability and motility rate of spermatozoa were measured. Within 56 h, the temperature of the cryopreserved spermatozoa was recorded at −43.5 ± 4.8 °C, nearly 30 °C warmer than the beginning of the experiment, −70.15 ± 2.90 °C. The present study revealed a high percentage of viability and motility rate of cryopreserved spermatozoa of E. lanceolatus, which were transported inside the styrofoam box using dry ice (−79 °C) as a cooling medium for 48 h and immersed back into the liquid nitrogen after 24 h and 48 h. Keywords: Dry ice, Cryopreservation, Shipping, Spermatozoa